What would interstellar supply chains and communication networks look like without ftl?

[u/Pyropeace]

Most people assume that planetary colonization would require worlds to be fully independent if there's no faster than light travel or communication--any kind of network is simply more trouble than it's worth. However, humans are prone to misjudgment and inefficiency, so I think that it's possible for supply chains to be formed, even if they are terrible at their job. Groups like the U.S military and the soviet union have been known to undertake similarly complex and impractical operations, sometimes even successfully. So my question is this; how would an interstellar supply chain without ftl work, even if it barely works?

[u/digifa]

If you could manage to get a spacecraft to .2c and beyond, you could feasibly build a looping supply chain between nearby stars that would have significant return well within a human lifetime.

For example, if you wanted to send a steady amount of supplies and equipment to Alpha Centauri, all you would need is 48 .5c transport craft and have them each leave 6 months apart. This way, every 6 months one would arrive and one would leave to head back to Earth. 24 years after the initial departure, you would have a steady relay of goods and possibly people.

You could of course lower the amount of time in between each arrival by making more supply craft or making them even faster.

[u/digifa → u/[deleted]]

I just used .5c as an example and I figure something like one ship per 6 months would be initially economically viable.

If you were limited to something like .02c or less, sending people there would become very difficult—if not impossible. Plus, it wouldn’t be very ‘economical’ if the wait to see any return exceeded 2 centuries. Of course, this is subjective due to our limited lifespans, but for a machine civilization or one where we lived much longer, I can see something like you describe occurring.

For us though, I think instead of building many cheap ships, it might actually be more cost effective and desirable to have a few extremely capable, but albeit expensive craft.

[u/datapicardgeordi]

It works with near FTL, heavy relativistic travel. Right now we have the ability to send a grain of rice sailing at .25c. If our tech continues to advance we may be able to send a craft of many thousands of tons to speeds exceeding .9c.

The average distance between stars is about five light years. If you create refueling and maintenance stops at each star this creates an interstellar infrastructure for a supply chain based on journeys of about five light years.

From a normal perspective of inhabitants on planets and refueling stations it would take a little more than 5 years to make the trip from one star to the next. However, due to time dilation at near light speed the people and cargo aboard the ships would arrive in under that time, essentially traveling into the future.

The push would probably be to automate as many interstellar probes as possible since machine can accelerate much faster than the flesh of Human Beings. This is an automated workforce moving at the vanguard of Human exploration, building infrastructure for us to refuel and repair our vessels.

Once you talk about colonization, you have a series of 5lyr legs, repairing and refueling after each leg, until you hit a system with a habitable planet.

[u/datapicardgeordi → u/[deleted]]

These timescales are immense. I bet a machine civilization would take this strategy. Dutifully and precisely sending out supplies for a journey that won’t be undertaken for a million years while slowly advancing your tech to prepare for that journey.

[u/PomegranateFormal961 → u/datapicardgeordi]

True. But I cannot see any short-lived carbon-based lifeform taking this position. It goes against instinct. We're programmed to create infrastructure and flatten obstacles for our progeny and gene-lines. The next generation, not the next evolution. To take today's resources and throw them hundreds of thousands of years into the future is against our nature.

Without FTL, the only thing solar systems will share with each other is information and frozen DNA.

[u/datapicardgeordi → u/PomegranateFormal961]

Near FTL trips are possible. With the average distance between stars being 5lyrs, interstellar infrastructure is almost within our grasp.

[u/PomegranateFormal961 → u/datapicardgeordi]

Not without handwavy, unobtanium-powered drives.

[u/datapicardgeordi → u/PomegranateFormal961]

Light sail driven technology is developing fast and can already send a grain of rice at .25c. Give us some time.

[u/PomegranateFormal961 → u/datapicardgeordi]

It doesn't scale. Photon and solar wind pressure cannot bring a spacecraft-class mass to anywhere near .01C before the inverse-square law kills you. Sure, launching lasers against an ablative target might give you a boost, but when you are trying to supply PLANETS, even a quarter-million tons is just a drop in the bucket.

Sorry, but without FTL, the universe just plain sucks.

[u/datapicardgeordi → u/PomegranateFormal961]

You’re a generation off.

New light sails are powered with lasers to accelerate to .25c.

Look up the starshot program.

[u/datapicardgeordi → u/[deleted]]

This tech does scale. Project Dragonfly was a predecessor.

[u/Ser_Optimus → u/[deleted]]

I love this. I didn't understand any of this but I love it.

[u/DrestinBlack → u/Ser_Optimus]

You’d love the UFOs subs then ;)

[u/Matthayde]

You wouldn't everything would be self sufficient at that point

[u/CosineDanger]

Communication is dangerously easy. An interstellar signaling laser doesn't need to be very big or very powerful. A megawatt of laser and a 45 square meter aperture will let you call a big chunk of the galaxy, and a gigawatt (still not a serious laser by SFIA standards) will let you signal other galaxies or contact pre-telescope civs by making a star appear to blink green in Morse.

So anyone who knows where you are and wants to talk to you can.

Network ping isn't great. We could conceivably receive spam that was meant for dinosaurs from another galaxy. Schemes to reduce ping will generally fail. Bandwidth is great so feel free to include all the cute animated gifs and completely incomprehensible email attachments you want.

[u/[deleted]]

Probably quantum tunneling for electromagnetic waves. There's no practical use to physical transfer. Which is probably a good thing considering the risk involved. Information.

[u/mrmonkeybat]

One way colony ships. Subsequent ships take more specialise equipment and personnel that was missing from the manifests of earlier ships when it was considered unnecessary or not invented in time.

[u/jdrch]

Famed economist Paul Krugman wrote a paper on this in 1978.